This invention relates to a plough for winning a mineral material, such as coal, from a mineral face or seam in a mine working.
In order to win coal in the roof zone of a mine working, particularly in seams of varying thickness, it is known to provide coal ploughs with roof cutters mounted on a vertically adjustable carrier. The level of the carrier may be adjusted by means of a worm gear having a worm meshing with a toothed rack. The worm is rotatably supported by the body of the plough, and the toothed rack is provided on the carrier. See (U.S. Pat. No. 4,275,927).
The worm gear of this known arrangement enables the level of the carrier to be varied infinitely. The worm is actuated by a hand lever which is mounted on the shaft which rotatably supports the worm in a chamber at the top side of the plough body. The worm is located at the side of the carrier. The carrier consists of a carrier plate which is coupled to a slide-like guide plate. The guide plate is provided with serrations, and so constitutes the toothed rack of the worm gear. Cutters are mounted on the carrier plate.
The aim of the invention is to provide a mineral winning plough having an improved form of roof cutter carrier adjusting means, and in particular an adjusting means which can be operated from the goaf side of the plough in a trouble-free manner, and by the application of a relatively low manual force.